Steam-generating furnace



Dec. 9, 1930. T. F. DowNEY ET AL 1,784,134

STEAM GENERATING FURNACE Filed May 5, 1928 3 sheets-sheet 1 T F owrzef Jnves rDon/(Lal,

De@ 9, 1930.L T. F. IDowNEY E1' AL v1,784,11'54 STEAM GENERATI NG FURNACE Filed May 5. 1928 5 SheebS--SheefI 2 @Um/i515: T Down/0g,

Jawves Bo wald,

Jammer;

Dec. 9, 1930,.

T. F. DOWNEY ET AL STEAM GENERATING FURNACE Filed May 5, 1928 5 SheeJcS--Sheel 3 Patented Dec. 9, 1930 UNITED STATES- THOMAS F.

PATENT: OFFICE um yJamas DONALD, or omesso, mLmoIs STEALGENERATING FURNACE Application led Hay 5,

Another object is to provide a gravity# feed furnace with a top water-wall of new and improved construction.

In the accompanying drawings, Figure 1 is a transverse vertical sectional view taken approximately in the line of 1-1 l5 of Fig. 5.` f

Fig. 2 is a section on line 2-2 o f Fig. 1.

Fig. 3 is a front elevation of the furnace.

Fig. 4 is a section on line 4-4 of Fig. 1.

Fig. 5 is a section on line 5,-5 of Fig. 1.

Fig. 6 is a perspective view of one of the elements comprised in the coal-feeding pockets.

F ig. 7 is a perspective view of one of the furnace-arch tiles.

Fig. 8 is a sectional view illustrating an alternative construction of the grates,

Although a furnace embodying the features of our invention may be used in connection with various types of boilers, we have herein shown it as associated with a Scotch boiler 1, the main flue of which is indicated at 2, and some of the fire tubes at 2.

The furnace is located in front of the boiler and in communication with the flue 2. The furnace is herein shown as comprising a front wall 3 and side walls 4 formed of steel plates. In the front wall is a fire door 3a and ashpit doors 3b. The furnace arch or water-wall comprises two parallel headers 5 each secured to one of the side walls 4 and extending longitudinally of said walls, together with a series of spaced parallel tubes 6 extending transversely across the furnace and connected at their ends to the headers 5. In the outer sides of the headers are clean-out openings 6 alined with the tubes 6.

Means is provided for supplying coal to the grate through the spaces between the tubes 6 adjacent to the headers 5. These spaces may be termed-feed pockets. They 1928. Serial lo. 275,495.

extend the full length ofthe grate on both sides of the furnace. In order to rotect the tubes 6 from abrasion, we provi e a series of castings 7 (Fig. 6), each consisting of a shield 8 of approximately semi-cylindrical form to fit upon one of the tubes 6, and flanges 9'on one end of the shield.A The anges 9 .form a continuous series extending-parallel with the adjacent header 5. The space ,bei

tween the two series of flanges 9 is covered by a steel plate 10. Between said two series of flanges 9 the tubes 6 are protected by means of tiles 11 which are supported by andsurround said tubes.

' As shown in Fig. 5, the len h of each tile 11 measured longitudinally o the furnace is one-half the distance between the centers of two adjacent tubes 6. Each tile has in one side a recess 12 to accommodate a tube 6. The tiles are installed initially before the castings 7 are put in place, the tiles being slid toward the center line of the furnace from the spaces adjacent to the headers 5. After the tiles are in place, the castings 7 are set upon the tubes.

with the damaged tile is removed, and the replacement made through the space normally occupied by said casting.

One of the headers5 is connected to the lower l a tube 13, while the other header 5 is connected to the upper portion of the boiler by means of a tube 14.

Attached to each of the headers l5 is an Means is provided for feeding coal from .the feed pockets to the. inclined grates and the bottom grate. In the construction shown in Fig. 1, said feeding means includes pusher When a tile requires re-l placement, the casting 7 which is in linev portion of the boiler-1 by means of members 18 which eccup the space between the u per ends of t e side grates 17 and the hea ers 5. Each pusher member is in the form of a rectangular casting which may have air openings 19 therethrough, as shown in Fig. 5. The pusher members 18 are fixed upon a shaft 20 which is supported in bearings at the upper end of the adjacent inclined side grate. When in normal or idle position the pusher members 18 are approximately in the same plane as the adjacent side grate, and support a quantity of coal extendin up -through the spaces between the shiel s 8.

Uponthe outer or lower side of each pusher member is a cut-off iange 21 which is curved upon the axis of the pusher member. The curved cut-olf flanges 21 form a substantially continuous series, as shown in Fig. 2, so that when the pusher members are swung in the direction to force coal onto the bottom grate, the cut-olf flanges close the -feed pockets and thus serve to revent coal from falling behind the pushe members.

The means herein shown for oscillating the pusher members 18 comprises a rock shaft 22 journaled in bearings on the side wall of the furnace and connected to several of the cutoff flanges 21 by means ofcrank arms 23 and links 24. On' the forward outer i.end of the shaft 22 is a hand lever 25 (Fig. 3) by means of which the shaft maybe rocked to oscillate the'pusher members. While hand levers have been herein shown for operating the pusher members, it'will vbe understood that power-actuated' means might be employed for that purpose.

Means is provided for supplying heatedl air to support combustion. An air pipe 26 extends longitudinall of the furnace and above the middle of tlyie tubes 6. Connected with said air pipe are transverse pipes 27 which extend above the spaces between the -tubes 6. Extending downwardl from each of the tubes 27 are tubes 28 w 'ch project into recesses 29 formed between adjacent tiles, said spaces extending to the lower sides of the tiles so as to allow air to be discharged directly over the fire. In the present construction, the recesses 29 are formed by chamfering the corners of the tiles. Inasmuch as the pipes 26, 27 and 28 are above the arch, they are effectivel re. The front end o t e pipe 26 is connected b means of a tube 30 to a suitable source o supply (not shown) of air under pressure. I esired, the tube 30 maybeconnected to a steam ipe, so that steam may be sprayed over the re.

In Fig. 8 we have shown an alternative construction of stoker grate. Only the righthand half of the grate structure is illustrated. This alternative construction comrises a center dump grate comprising grate vhars 31 pivoted at 32. to swing downwardly rotected from the to dump the ashes. The means for operating the grate bars 31 comprises a shaft 33 having thereon a suitable number of crank arms 34 and links 35. At each side of the center dump grate is an inclined set of grate bars l comprising, in this instance, two longitudinal series of stationary grate bars 36 and 37 and two series of pusher members 38 and 39 similar to the members 18 hereinbefore described. Normally, the and the pusher members 38 and 39 lie in the same inclined plane.

'The means for operating the upper series of pusher members 38 is generallv similar to that shown in Figs. 1 and 2, and comprises a shaft 40 which is connected to the pusher members 38 through 'the medium of crank arms 41 and links 42. Similarly, the series of pusher members 39 are operated b means of a shaft 43, crank arms 44 and lin 45.

The shafts 40 and 43 are arranged to be simultaneously rocked by means of crank arms 46 and 47, respectively, which are connected to crank arms 48 and 49 on a shaft 5() by means of connecting rods 51 and 52. The shaft 50 may be rotated by any suitable means, as, for example, worm gearing 53 connecting said shaft to a transverse shaft 54.

In operation, coal is fed asrequired to the grates by means of the pivoted pusher meinbers. The heated ai'r supplied above the lire insures proper combustion, the hot gases entering the main iue 2 of the boiler and thence circulating through the ire tubes 2. The heat within the furnace sets up a flow of water from the lower portion of the boiler through the tubes 6 to the upper portion of the boiler, thus securing approximate uniformity of Water temperature in the boiler and thereby correcting a well-known disadvantage of the Scotch type of boiler.

grate bars 36 and 37 If desired, the fuel feed openings may be closed in any preferred way, and the furnace operated by means of an oil burner. When oil is to be burned, the grates are removed, and the side walls 4 protected by brickwork.

Various changes may be made in the construction and relative arrangement of the parts herein shown. For example, the form of bottom grate shown in Fig. 8 may be used .in connection with the form of side grates shown in Fig. A1.

We claim as our invention: 1. A steam-generating furnace comprising 'a grate, and a tileprotected water-wall over the grate comprising a series of spaced parallel water tubes extending transversely of the furnace, a header at each side of the furnace connected to said tubes, there being fuel feed openings between said tubes adjacent to lsaid headers, a series of members for each of said series of fuel feed openings, each of said members comprising a Vsemi-cylindrical shield for one of said tubes and flanges at one end of the shield, said flanges forming a substantially continuous series adjacent to and parallel with one of said headers, and tiles enclosing that portion of each tube which extends between the said series of flanges.

2. A furnace comprising a grate, and a tile-protected water-wall over the grate comprisingva series of spaced parallel water tubes extending transversely of the furnace, a header at one side of the furnace connected to one end of each tube, means connecting the opposite ends of the tubes, there being' fuel feed openings between said tubes adjacent to said header, a semi-cylindrical shield for that portion of each of said tubes which is adjacent to said header, and means projecting laterally from one end of each shield, said lastmentioned means forming a substantially continuous series adjacent to and parallel with saidheader whereby to define one side of `said fuel feed openings.

3. A steam-generating furnace comprising a gra-te, and a tile-protected water-wall over the grate com rising a series of spaced parallel water tu es extending transversely of the furnace, a. header at each side of the furnace connected to said tubes, there being fuelfeed openingsbetween said tubes forming a series of openings adjacent to said headers through which coal may be fed, and means enclosing the upper part ofthat portion of eachtube which extends between the adjacent feed openingsV and servin to protect said tubes from wear by the co passing through said openings.

4. A furnace comprising a grate, al tilerotected water-wall over the grate having el openings formed at the sides thereof, means extending. along the top of said waterwall for supplying heated air, nozzles extendin throug said water-wall, a plate extending over said means from the openings on one side of said wall to the openings on the other side thereof, and inclined plates extending longitudinally of the furnace along the outer edges of said openings so that fuel may be piled on said plate to be fed through said openings into the furnace. f

5. A steam-generating furnace comprising a ate, and a water-wall over the grate comprising a series of spaced parallel water tubes extending transversely of the furnace, a header at each side of the furnace connected to said tubes, there being fuel feed openings in said wall between said tubes forming a series of feed openings adjacent to said headers through which fuel may be fed, a shield of semi-circular cross section positioned over the top of each'tube at each end adjacent to the headers to protect said tubes .from wear by the fuel passing through said openings, and two rows of tiles between each adjacent pair of tubes abutting at their sides and ends and enclosing that portion of each individual endwise withdrawal of said tiles when the corresponding shieldv is removed.

6. A steam-generating furnace comprising means forming a combustion chamber and including a water-wall across the top of said chamber, said wall comprising a series of spaced parallel water tubes extending across the top of the chamber,'a header positioned at each end ,of said tubes and connected thereto, two rows of tiles between each adjacent pairs of tubes abutting at their sides.a`nd ends and enclosing substantially the entire lengthl of said tubes, each tile havin a longitudinally extending recess in one si e thereof embracing the side, top and bottom of the adjacent tube, and a plurality of tube-protecting members movable downwardly onto the tubes to protect a part of the surface ofsaid tubes and abut the tiles to prevent endwise displacement thereof, said members being'of greater length than said tiles whereby to permit endwise withdrawal of the tiles when the abutting members are removed. y

In testimony whereof we have hereunto aixed our signatures.

` THOMAS F. DOWNEY.

`JAMES DONALD.

downwardly from said means 

